Enhancement and monitoring of nesting habitat for Common
Loons (Gavia immer) on Whatshan Lake Reservoir and Upper
Arrow Lakes Reservoir
Prepared for BC Hydro Fish and Wildlife Compensation Program ‐ Columbia
Mandy Kellner and Harry van Oort
Kingbird Biological Consultants Ltd.
Revelstoke BC
250‐837‐0820
Dec. 2013
Kingbird Biological Consultants: Loon habitat enhancement and nesting success 2013
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ExecutivesummaryCommon Loons (Gavia immer) are large, piscivorous birds that nest on the shoreline of lakes,
immediately adjacent to the water. At Whatshan Reservoir in southeastern British Columbia,
construction of a dam and flooding of original wetland and riparian habitats has likely led to the
reduction of suitable nesting habitat. Further affecting the productivity of loons at Whatshan, are
disturbance from human development and recreation on the reservoir, and the flooding of nests
through reservoir operations. Floating nest platforms have been used successfully to increase loon
reproductive success in other lakes and reservoirs, and could help mitigate negative impacts of reservoir
operations and encourage the loons to nest away from areas prone to human disturbance. In response
to a low rate of reproductive success documented during previous work, we installed five floating
artificial nest platforms in 2011. The platforms were planted with graminoids, emergent plants, and
shrubs, which grew vigorously and by mid‐summer, they were vegetated enough to appear as riparian
habitat, adding diversity to the reservoir and potentially offering resting, foraging, or cover habitats to
wildlife. No loons nested on the platforms in their year of instalment.
Monitoring for loon usage continued in the 2012 nesting season. However, water levels that were 3‐4m
below norm in spring (mid‐ to late‐May) meant that loons could not access the stranded platforms
during the start of the nesting period. Nevertheless, after the reservoir filled, one of the platforms was
used by loons for nesting. This nest did not succeed, due to either predation of eggs or young shortly
after hatching. Of the four territorial pairs of loons present on the lake, only one pair was successful in
hatching a single chick (1/4 pairs, 25% success). This successful nest was also on a floating platform, an
old dock also used in previous years as a nest site.
Monitoring continued for 2013, and use of the platforms by loons increased dramatically, with three of
four nesting pairs using artificial platforms. Two of these pairs successfully nested and raised young; the
third pair failed to incubate their egg, for reasons unknown. The fourth breeding pair nested on the
shore of an island, and the nest was inundated as the water level rose. Overall, two of the four breeding
pairs reproduced successfully this year (2/4 pairs, 50% success). Perhaps equally as important, the
successful young were hatched around June 12 and June 24, much earlier than hatch dates of successful
nests in the past.
As in previous years, the condition of the floating structures and associated vegetation was
documented. All five platforms survived the winter and remained anchored in their original positions.
However, inspection in April showed variable amounts of damage from mammals and/or ice or wind,
and some significant wear and tear on the original anchoring systems. These problems were addressed
through re‐vegetation and replacement of worn components, but should be considered for future
installations.
New this year was the addition of a floating island nest platform to Montana Slough, near Revelstoke.
This site is frequently used for nesting by loons but often suffers from nest inundation as reservoir levels
rise, similar to at Whatshan Lake. This platform was installed after nesting had begun, and did not
receive any use in 2013.
Kingbird Biological Consultants: Loon habitat enhancement and nesting success 2013
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KeywordsCommon loon, Gavia immer, reservoir, nesting success, nesting habitat, artificial nesting platform,
Whatshan Lake, Montana Slough, Upper Arrow Lake
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TableofContentsExecutive summary .......................................................................................................................................2 Keywords.......................................................................................................................................................3 Table of Contents..........................................................................................................................................4 List of Figures ................................................................................................................................................4 List of Tables .................................................................................................................................................5 Introduction ..................................................................................................................................................6 Introduction ..................................................................................................................................................6 Study area .....................................................................................................................................................7 Methods........................................................................................................................................................9
Platform installation .............................................................................................................................9 Monitoring of nest platforms and loon reproductive success............................................................10 Data analysis and management..........................................................................................................10
Results.........................................................................................................................................................10 Use of platforms by loons ...................................................................................................................11 Nesting success and timing.................................................................................................................11 Platform condition and maintenance .................................................................................................12 Other wildlife ......................................................................................................................................14
Discussion and management implications..................................................................................................14 Use of platforms and nesting success.................................................................................................14 Platform condition ..............................................................................................................................15 Recommendations ..............................................................................................................................16
Acknowledgements.....................................................................................................................................16 References ..................................................................................................................................................17 Appendix 1. Loon nest information ...........................................................................................................19 Appendix 2. Photo log of platform condition and plant development on platforms during Year 3 ..........21 Appendix 3. Incidental observations of wildlife at Whatshan Lake, 2013..................................................24
ListofFiguresFigure 1. Map showing the location of Whatshan Lake in south‐central British Columbia. ........................8 Figure 2. Map showing the location of Montana Slough on the Upper Arrow Lake Reservoir, near
Revelstoke, in south‐central British Columbia..............................................................................................9 Figure 3. The Montana Slough platform wrapped in wire, prior to planting. ............................................10 Figure 4. Reservoir elevation for Whatshan Lake Reservoir in 2013, minimum water levels prescribed by
the WUP, and the initiation dates for successful and unsuccessful nests. Both successful nests were on
floating platforms; 1 unsuccessful nest was on a platform but not incubated, and one was on shore and
was inundated.............................................................................................................................................12
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Figure 5. The Flicker Lagoon platform in April 2013 (left), showing the loss of buoyancy due to the
removal of matrix material by small mammals. The platform did dry out and support plant growth, and
attracted nesting loons (right). ...................................................................................................................13 Figure 6. The Lagoon platform in late April 2013 (left), showing loss of soil and vegetation, potentially
caused by ice, waves, or mammals. Although not totally vegetated by late June, this platform was re‐
planted and grew some vegetation, and attracted nesting loons (right)...................................................14 Figure 7. Successful nests on Whatshan Lake in 2013: the South End platform nest SE‐1‐13, located on
May15 (left), and the Lagoon platform nest LG‐1‐13, located on May 28 (right). .....................................20 Figure 8. Unsuccessful nests located at Whatshan Lake in 2013: the White Grouse shore nest WG‐1‐13
on May 28 (left) and the Flicker Lagoon platform nest FL‐1‐13 on June 12, which appeared to not be
incubated (right). ........................................................................................................................................20 Figure 9. Flicker Lagoon (FL) platform in late April (left), May (centre), and late June (right). The platform
was excavated by small mammals in the winter, leading to loss of buoyancy. However, it dried out in the
summer and was used for nesting, although the nest failed. ....................................................................21 Figure 10. The Loongoon (LG) platform in late April (left) showing damage from ice or mammals, its use
by loons in May (centre), and its state in late June after the nest hatched (right). ...................................21 Figure 11. The North End (NE) platform in May (left) and at the end of the growing season in August
(right). .........................................................................................................................................................22 Figure 12. The South End (SE) platform still stranded on Apr 28 (left), and being used for nesting in late
May (right). .................................................................................................................................................22 Figure 13. The White Grouse (WG) platform in late April (left), late May (centre), and late June (right). 23 Figure 14. The Montana Slough (MO) platform when first deployed in May (left), after being heavily
grazed by Canada Geese in June (centre), and regrown after Geese moved on, in July (right).................23
ListofTablesTable 1. Start dates for successful nests at Whatshan Lake, year of nest, and substrate used for nesting.
Note early start dates for nests on artificial nest platforms, and paucity of successful shore nests. ........15 Table 2. Location, descriptions, and fates of loon nests on Whatshan Lake and Montana Slough, Upper
Arrow Lake, 2013. .......................................................................................................................................19 Table 3. Incidental wildlife observations, 2013. .........................................................................................24
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IntroductionCommon loons (Gavia immer) nest immediately next to the water’s edge, often amongst emergent
vegetation (Campbell et al 2008), and select diverse micro‐sites such as muskrat mounds, floating or
emergent logs, bare ground, or floating bog mats, with floating mats offering the best chance of nesting
success (McIntyre and Barr 1997). On Whatshan Lake Reservoir (and elsewhere in the Columbia Basin)
much of the higher‐quality nesting habitat along the lakeshore was likely lost with reservoir creation,
and was replaced largely by the steep dry banks that surround much of the reservoir at present (Utzig
and Schmidt 2011). Areas within Whatshan Lake Reservoir that appear to offer suitable nesting habitat
become flooded by rising reservoir levels each spring.
Potentially compounding the impacts from reservoir creation and operations are other factors known to
be detrimental to loon nesting success, such as the waves created by motorized recreation on the
reservoir and the shoreline development along the southern lake. Four years of data on loon
reproductive success and timing of reproduction on Whatshan Lake between 2006 and 2010 have
shown that most pairs of loons do not successfully reproduce and that reproductive rates are low (0 – 50
% of nests are successful per year) (van Oort and Kellner 2007, 2008, Kellner and van Oort 2009, 2011a,
b), compared to the Canadian average of 50% or better (Timmermans and Jones 2002). Over the 4 years
of monitoring 4 or 5 loon pairs each year, 4 nests were confirmed (and others suspected) to have failed
due to rising water levels flooding nests built on shore or on unstable floating substrates (Kellner and
van Oort 2011b). Other causes of nest failure were suspected human disturbance and suspected
predation.
An indirect negative impact to the productivity of loons nesting on Whatshan Lake Reservoir is that
successful nests are commonly initiated near or after the reservoir has reached full pool. This results in
later dates for nest initiation (Kellner and van Oort 2011a,b), compared with other records from the
West Kootenay which document nesting in early‐ to mid‐May (Campbell et al 2008), and also results in
late hatching of young, with potential consequences for winter survival and juvenile recruitment.
Research in other regions has shown that loons readily use artificial floating nest platforms (McIntyre
and Barr 1997, Piper et al 2002), and that reproductive success can increase when nesting platforms are
used (Piper et al 2002). In British Columbia, the use of floating nest platforms has been suggested as a
“management tool” for loon populations on reservoirs (Campbell et al 2008). Any efforts to improve the
nesting success of common loons are especially relevant in light of new research detailing a long‐term
decline in the number of fledged young per breeding pair of loons across southern Canada (Tozer et al.
2013). Several factors make Whatshan Reservoir a suitable site for enhancement using floating nest
platforms. The reservoir has a convoluted shoreline, with secluded lagoons and bays that offer prime
nesting locations. The reservoir also has a relatively small drawdown height, simplifying anchoring
systems. Additionally, data is available on reproductive success, timing of nesting, and causes of nest
failure prior to enhancement, to which the post‐enhancement data can be compared. Five floating nest
platforms were installed at Whatshan Reservoir in 2011. However, nesting was underway at that time
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and the platforms were not used by loons in the initial year (Kellner and van Oort 2011a). In 2012, the
platforms were used by one pair of loons, in spite of the unusual water levels fluctuations in that year.
In 2013, we continued to monitor the use of platforms by loons and the reproductive success of loons
on the reservoir. We documented the durability of the platforms and state of associated vegetation
after two full years of deployment, to assess the suitability, long term durability, and future
maintenance requirements of this technology for enhancement work in Whatshan and other BC
reservoirs. We also expanded the project with the installation of a floating nest platform in Montana
Slough, Upper Arrow Lakes Reservoir, near Revelstoke, in late May 2013, and monitored the use by
loons and the growth of vegetation on this platform.
StudyareaEnhancement work and monitoring was done on Whatshan Lake Reservoir, at 5 locations known to be
within territories of common loons. In 4 cases, the platforms were located at known nesting sites.
Whatshan Lake Reservoir is west of Lower Arrow Lake, immediately north of Hwy 6 at the Needles ferry,
and approximately 55 km southwest of Nakusp, BC (Figure 1. Map showing the location of Whatshan
Lake in south‐central British Columbia..
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Figure 1. Map showing the location of Whatshan Lake in south‐central British Columbia.
The reservoir is approximately 17 km long with a convoluted shoreline and a number of lagoons and
islands. The reservoir supports considerable fish stocks and is valued for its recreational fishery. The
southern end of the reservoir is characterized by high levels of shoreline cottage development and is
used heavily during the summer months for motorized water sports. Water level fluctuations at the
Whatshan Lake Reservoir are controlled throughout the year by the operations of the hydroelectric
power generating plant. These operations are detailed by the Whatshan Lake Reservoir Water Use Plan
(BC Hydro 2005). In this document, it was prescribed that the water levels should be maintained at or
above: 636.5 m during the winter; 639.1 m elevation from May 15th to June 14 th; and, 640.35 m from
June 15 th to October 1st. These target water levels were developed to benefit recreational quality and
fish populations of the reservoir.
Enhancement and monitoring was also done at Montana Slough, Upper Arrow Lakes Reservoir, near a
known nesting site for common loons. Montana Slough is 4 km south of Revelstoke, on the east side of
Upper Arrow Lakes Reservoir (Figure 2). This wetland complex is positioned at ~436 m elevation. The
wetland becomes flooded when the Upper Arrow Lakes Reservoir elevation exceeds 436 m. An
interesting feature of Montana Slough is a floating bog mat that provides riparian habitat as water
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elevations rise, but this mat becomes gradually inundated and has proven to be an unreliable nesting
substrate for loons in previous years (HvO personal observation).
Figure 2. Map showing the location of Montana Slough on the Upper Arrow Lake Reservoir, near Revelstoke, in south‐central
British Columbia.
Methods
PlatforminstallationLoon nesting platforms were pre‐fabricated by Floating Islands West, California
(http://www.floatingislandswest.com). They are approximately 2m X 1.5m in size, and constructed with
durable non‐toxic plastic mesh product that can acts as a rooting substrate for vegetation (Figure 3).
Before planting, the new platform at Montana Slough was entirely wrapped in chicken wire to deter
small mammals from damaging it (Figure 3). Wire cutters were used to create holes for planting, above
each of the planting wells in the original platform. It was then located and planted following the
protocols used for the five platforms at Whatshan Lake (Kellner and van Oort 2011). The exact location
for anchoring was determined by locating the deepest area of Montana Slough from bathymetric maps
(Hawkes et al. 2011), plus considering the location of previous known loon nests.
The platform was anchored with a pulley‐system on each side, to allow the platform to float without
rotating as the reservoir rises, while keeping slack out of the system at lower water levels. Platform
location was chosen so that the water depth (~6 m) at low reservoir elevations exceeded the amount of
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rise needed in the cable to allow the platform to float at full‐pool (~4 m) – thus, the counterweights
should never become grounded, reducing the potential for slack in the lines and possibly entanglement.
Figure 3. The Montana Slough platform wrapped in wire, prior to planting.
MonitoringofnestplatformsandloonreproductivesuccessWe monitored the condition and use of artificial nest platforms and the reproductive success of
Common Loons, from late April to late July, 2013, using the protocol of Kellner and van Oort (2011b).
Monitoring was conducted, weather‐permitting, using a canoe and two observers. If the weather was
not conducive to boating, monitoring occurred from shore where possible. For each of the five platforms
in the territories previously identified on Whatshan Lake (Kellner and van Oort 2011a,b), and for the
Montana territory, we visited nest platforms to assess platform condition and look for use by loons. We
attempted to locate loon pairs, and their nest sites if possible, and determine the number of eggs and
fate of these nests. If loon pairs were accompanied by young, the number, size, colour, and behaviour of
young were recorded (McIntyre and Barr 1997). When a loon or nest was located, a handheld global
positioning system (Garmin Map76CSX) was used to record its location on the reservoir.
DataanalysisandmanagementData from field notebooks were entered in an Excel spreadsheet after each survey. All waypoints were
downloaded and saved on computer, and projected in ArcView to check accuracy of the waypoints and
associated field notes. Data on nest locations and success and the final report are to be submitted to the
Province of BC through the Wildlife Species Inventory submission site. Data on nesting success will also
be submitted to the Canadian Lakes Loon Survey.
We examined observations to estimate dates for nest initiation, start of incubation, and hatching. We
calculated nesting success per year as the number of loon pairs observed with young divided by the
number of territorial loon pairs observed in spring.
Results
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UseofplatformsbyloonsAt Whatshan Lake Reservoir, loons nested on three of the five platforms (South End, Lagoon, and Flicker
Lagoon). A fourth loon pair nested on a rocky shore very near a platform (White Grouse), while in the
fifth territory (North End), we did not observe any loons exhibiting nesting behaviours (paired birds,
localized activity), although a single loon was seen very near the platform. Water levels in 2013 followed
recommendations in the WUP (Figure 4), and although several platforms were still beached in late April,
all were available to loons by our next visit on May 15. At this time, the South End pair was already
incubating their nest on a platform.
At Montana Slough, nesting was underway when the platform was first installed, and no loons used the
platform in 2013.
NestingsuccessandtimingWe located four nests from the four territorial pairs of loons on Whatshan Lake this year. Three were
established on the floating island nest platforms, in the South End, Lagoon, and Flicker territories; these
were first observed with eggs or incubating on May 15, May 28, and June 12, respectively (Figure 4).
One nest, for the White Grouse pair, was not on a floating platform. It was located on May 28 on the
rocky shore of an island just above the water level, and was likely inundated shortly after it was
observed. No re‐nesting attempt was observed after the initial nest site was flooded.
Two of the four breeding pairs on Whatshan Lake Reservoir successfully hatched young in 2013 (50% of
pairs were successful). Two small black young were observed in the South End territory on June 12.
Large, undisturbed eggshell fragments at the Lagoon nest suggested that one young hatched on
approximately June 24. The nest on the platform at Flicker Lagoon appeared to not be incubated and did
not hatch.
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Date
01-Apr 01-May 01-Jun 01-Jul 01-Aug
Re
serv
oir
ele
vatio
n (
m)
634
635
636
637
638
639
640
641
2013 reservoir elevation (m)WUP minimum elevationInitiation date of successful nestsInitiation date of failed nests
Figure 4. Reservoir elevation for Whatshan Lake Reservoir in 2013, minimum water levels prescribed by the WUP, and the
initiation dates for successful and unsuccessful nests. Both successful nests were on floating platforms; 1 unsuccessful nest
was on a platform but not incubated, and one was on shore and was inundated.
At Montana Slough, loons were nesting when the platform was installed on May 28. This nest
subsequently failed by May 27, and the pair re‐nested on the shore in late June when the reservoir was
full. Falling water levels left this nest stranded well above the water’s edge, and it was abandoned in late
July, likely just before hatching. Information on nest locations and fates is detailed in Appendix 1.
PlatformconditionandmaintenanceAll five platforms at Whatshan were still anchored as placed, but required some maintenance for
hardware and vegetation. One anchor cable was worn through (North End platform), and we replaced
that cable and several others that showed signs of wear. These anchors were re‐attached using an
improved system that did not require removing the protective rubber casing from the cables.
As previously, there was some rodent damage (likely from Deer mice (Peromyscus maniculatus)) found
upon first inspection in late April – notably at the North End, Lagoon, and Flicker Lagoon. The damage
constituted of tunnelling through the soft inner matrix. The platforms appeared to suffer some loss of
buoyancy due to removal of this matrix but dried out as the summer progressed (Figure 5. The Flicker
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Lagoon platform in April 2013 (left), showing the loss of buoyancy due to the removal of matrix material
by small mammals. The platform did dry out and support plant growth, and attracted nesting loons
(right). The vegetation on the platforms also showed damage, either from mammals or ice or wave
action. In one case (Lagoon), the damage was fairly extensive and required new soil and re‐planting
(Figure 6. The Lagoon platform in late April 2013 (left), showing loss of soil and vegetation, potentially
caused by ice, waves, or mammals. Although not totally vegetated by late June, this platform was re‐
planted and grew some vegetation, and attracted nesting loons (right).Error! Reference source not
found.). This platform had otter (Lontra canadensis) scat on it, suggesting mustelids may have played a
role in removing the soil and plants.
As in 2012, the vegetation on all platforms looked surprising poor in April and early May, but quickly
became lush, with excellent plant survival and growth as the growing season progressed (Appendix 2). A
wide variety of vegetation continued to grow well on the platforms, including grasses, sedges, rushes,
cattails, various other herbaceous plants, alder, and willow. Platforms were once again left in place for
winter 2013/2014.
Figure 5. The Flicker Lagoon platform in April 2013 (left), showing the loss of buoyancy due to the removal of matrix material
by small mammals. The platform did dry out and support plant growth, and attracted nesting loons (right).
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Figure 6. The Lagoon platform in late April 2013 (left), showing loss of soil and vegetation, potentially caused by ice, waves,
or mammals. Although not totally vegetated by late June, this platform was re‐planted and grew some vegetation, and
attracted nesting loons (right).
OtherwildlifeAt Whatshan Lake, two platform showed signs of fall, winter, or early spring use by otters, based on the
presence of old scat containing fish bones and scales. Three platforms were disturbed by deer mice or
other small mammals, which excavated tunnels into the plastic matrix during the winter months when
the platforms were grounded. As in previous years, after water levels rose, damage from small
mammals ceased. The Montana platform was used extensively by Canada Geese (Branta canadensis) for
resting and grazing. It also housed at least three young Western Toadlets (Bufo boreas) in mid‐summer.
A list of other incidental wildlife observations is included as Appendix 3.
Discussionandmanagementimplications
UseofplatformsandnestingsuccessAs anticipated based on the literature (Piper et al 2002, DeSorbo et al 2007), the use of platforms by
loons increased greatly in 2013, several seasons after being deployed. This is the third summer that the
Whatshan platforms have been in the water, and the loons are obviously familiar with the structures
and find them appealing. The platform at Montana Slough will hopefully attract loons in 2014. The
success of two nests on platforms alleviates concerns about possible increased predation of nests on
platforms. Nevertheless, it seems prudent to ensure that sticks or shrubs remain in place on the
platforms as protection against avian predators.
We documented the platforms at Whatshan and Montana being used by several species other than
loons, including small mammals, otters, Canada Geese, and Western Toads. Use by other species may
have occurred but not been detected. The vegetated islands clearly add to the diversity of habitats
available, and potentially benefit many wildlife species through providing foraging habitat, resting spots,
or cover.
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In previous years of study at Whatshan lake Reservoir, loons used a variety of natural and man‐made
floating structures, as well as sites along the shore, to nest on. Results in 2013 (two successful platform
nests, one flooded shore nest) support the idea that nests on floating platforms are more likely to
succeed than those on shore, in this reservoir (Kellner and van Oort 2011a,b, Kellner and van Oort 2012)
and elsewhere (McIntyre and Barr 1997, Piper et al 2002). This project has succeeded in increasing the
number and relative permanence of available floating structures at Whatshan Lake Reservoir, as well as
locating the available structures farther away from human disturbance.
The floating platforms allowed successful nests to be initiated earlier than if nests were on shore, where
nests can only be initiated successfully once the reservoir is near full pool. The two successful nests in
2013 had very early initiation dates relative to those in previous years (Table 1), even in relation to nests
on other floating substrates (a dock and natural floating platforms such as root balls). Since delayed
nesting is thought to potentially have implications for size at fall migration, juvenile survival, and future
reproduction (Newton and Marquiss 1984, Hochachka 1990, Naef‐Daenzer et al. 2001), hopefully the
early nesting dates at Whatshan increase the chances that juvenile loons survive to adulthood, to be
recruited into the breeding population.
Table 1. Start dates for successful nests at Whatshan Lake, year of nest, and substrate used for nesting. Note early start dates
for nests on artificial nest platforms, and paucity of successful shore nests.
Incubation start date for successful nests Year Nest substrate
May 15 2013 Nest platform
May 19 2011 Natural floating platform
May 28 2013 Nest platform
May 30 2010 Shore
Jun 8 2012 Floating dock
Jun 6 2008 Shore
Jun 6 2008 Natural floating platform
Jun 15 2009 Natural floating platform
Jun 25 2011 Shore
PlatformconditionThe platforms and anchoring systems were generally in good condition after two winters. The main
issues and repairs were:
1. damage by small mammals and/or possibly otters. The new platform at Montana was wrapped
in chicken wire before deploying. The state of the wire will be assessed in spring 2014. There
were concerns that the texture of the wire may deter birds; however, the wire‐wrapped
platform was heavily used by geese, suggesting that it will be ok. Planted platforms cannot be
retro‐fitted with wire. Future installations should consider a wire treatment or discuss options
with the manufacturer.
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2. corrosion and breaking of some anchor cables – these were replaced using a new attachment
system used that does not require stripping of the protective plastic coating, and should
therefore not suffer from corrosion issues. This system will be assessed in 2014.
Entangling of cables, noticed in 2012, was not a problem in the spring of 2013. However, because of the
low water levels in winter and the abundance of stumps and logs in the reservoir, entanglement is likely
always going to be a potential problem at Whatshan. The Montana Slough platform should not suffer
from entanglement, because the water is sufficiently deep to allow counterweights to remove slack
form the anchor system, without the counterweights and lines getting ‘grounded’. This is certainly a
preferable scenario for deploying platforms, but may be relatively rare in areas of reservoirs used as
nesting sites.
Because of these issues, it is important that the anchoring systems and floatation of the platforms
should be checked every spring to ensure that the platforms are correctly positioned and functioning
properly, as recommended in 2012. We continue to agree with the manufacturer that it seems
unnecessary to remove platforms over‐winter, unlike the recommended protocol for conventional cedar
rafts (NALF 2005, DeSorbo et al 2008). This makes Floating Islands attractive for enhancement work
since they do not require scheduled yearly spring installation and fall removal.
RecommendationsBased on the need to do spring maintenance, and the excellent results of increasing platform use in
2013, we recommend another year of monitoring the state and use of platforms and the reproductive
success of loons at Whatshan and Montana Slough. Specifically,
Because of the unusual conditions in 2011/2012, and guidelines suggesting 3 years of monitoring as
appropriate to determine the level of use of platforms (DeSorbo et al 2007), we recommend another
year of monitoring, similar to the previous year, and including:
1. a site visit early spring to ensure that anchoring systems are functioning properly and platforms
are properly buoyant under normal water levels,
2. inspection of all anchor cables for wear and potentially converting them all to the new system, if
the few cables repaired in 2013 have over‐wintered well,
3. monitoring of use of platforms or natural nests by loons in early May and June, with efforts to
determine causes of any nest failures on platforms,
4. monitoring hatching success of loons in July, and
5. write‐up and publishing of results from platform installations as a peer‐reviewed paper,
documenting findings about the platforms and anchoring systems, as well as the use of
platforms by loons and implications on reproductive success.
AcknowledgementsFinancial support was contributed by the Fish and Wildlife Compensation Program‐ Columbia. We are
especially grateful to Irene Manley for her ongoing support and enthusiasm. We are grateful to Cooper
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Beauchesne and Associates Ltd., who provided information regarding the nest monitored in Montana
Slough as part of the BC Hydro CLBMON‐36 project.
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Appendix1.Loonnestinformation
Table 2. Location, descriptions, and fates of loon nests on Whatshan Lake and Montana Slough, Upper Arrow Lake, 2013.
Date located Reservoir‐Territory Nest ID UTM_X UTM_Y Description # eggs Fate
15‐May‐13 Whatshan‐ South End SE‐1‐13 419813 5529965 On platform 2 Hatched 2 young approximately 10
Jun.
28‐May‐13 Whatshan‐ Lagoon LG‐1‐13 421590 5535075 On platform. Mud and grass
nest.
2 Hatched 2 young (based on eggshell
fragments) approximately 20 Jun.
28‐May‐13 Whatshan‐ White
Grouse
WG‐1‐13 421255 5539469 Scrape amongst rocks on
shore of island; very close to
floating island.
1 Failed – flooded.
12‐Jun‐13 Whatshan‐ Flicker FL‐1‐13 421934 5536265 On platform. 1 Failed ‐ pair did not incubate.
15‐May‐13 Arrow ‐ Montana MO‐1‐13 418762 5643927 Mud and grass, on natural
floating bog mat.
Unk Failed – flooded.
21‐Jun‐13 Arrow‐ Montana MO‐2‐13 418677 5643988 Grass, on bog mat. 2 Failed – stranded as water levels
dropped.
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Figure 7. Successful nests on Whatshan Lake in 2013: the South End platform nest SE‐1‐13, located on May15 (left), and the
Lagoon platform nest LG‐1‐13, located on May 28 (right).
Figure 8. Unsuccessful nests located at Whatshan Lake in 2013: the White Grouse shore nest WG‐1‐13 on May 28 (left) and
the Flicker Lagoon platform nest FL‐1‐13 on June 12, which appeared to not be incubated (right).
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Appendix2.PhotologofplatformconditionandplantdevelopmentonplatformsduringYear3
Figure 9. Flicker Lagoon (FL) platform in late April (left), May (centre), and late June (right). The platform was excavated by small mammals in the winter, leading to loss of
buoyancy. However, it dried out in the summer and was used for nesting, although the nest failed.
Figure 10. The Loongoon (LG) platform in late April (left) showing damage from ice or mammals, its use by loons in May (centre), and its state in late June after the nest
hatched (right).
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Figure 11. The North End (NE) platform in May (left) and at the end of the growing season in August (right).
Figure 12. The South End (SE) platform still stranded on Apr 28 (left), and being used for nesting in late May (right).
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Figure 13. The White Grouse (WG) platform in late April (left), late May (centre), and late June (right).
Figure 14. The Montana Slough (MO) platform when first deployed in May (left), after being heavily grazed by Canada Geese in June (centre), and regrown after Geese
moved on, in July (right).
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Appendix3.IncidentalobservationsofwildlifeatWhatshanLake,2013Table 3. Incidental wildlife observations, 2013.
Date Location Species Number Comments
28‐Apr S end mallard 2
28‐Apr S end Canada Geese
28‐Apr S end Varied Thrush
28‐Apr S end Black‐capped chickadee
28‐Apr S end Dark‐eyed junco
28‐Apr S end ruby‐crowned kinglet
28‐Apr S end moose 1 tracks in drawdown zone
28‐Apr Loongoon wolf 1 tracks in drawdown zone
28‐Apr Loongoon otter scat on platform
28‐Apr White Grouse wolf scat in drawdown zone
28‐Apr White Grouse otter scat on platform
28‐Apr S end of N lake kingfisher 1
28‐Apr Flicker kingfisher 3 flying high screeching
28‐Apr N end osprey 1
28‐Apr N end common merganser 2
28‐Apr N end scaup 2
28‐Apr N end S lake common merganser 2
28‐Apr Flicker deer 2 in drawdown zone
28‐Apr Loongoon swallows
28‐Apr Flicker swallows
13‐May S end deju
13‐May S end yrwa
13‐May S end flycatchers
13‐May S end osprey 1 on nest along powerline
13‐May Loongoon nuthatch
13‐May Loongoon osprey
13‐May Loongoon Canada Geese
13‐May Loongoon yrwa
13‐May Loongoon robin
13‐May Loongoon flycatchers
13‐May Flicker red eyed vireos
13‐May White Grouse Canada Geese 4 fluffy yellow young
27‐May Montana Canada Geese not seen, but platform is covered in droppings
28‐May N end swainson's thrush
28‐May N end flycatchers
28‐May S end osprey incubating nest on powerline
26‐Jun S end N lake kingfisher
26‐Jun Middle lake Grebe ‐ eared? Horned?
26‐Jun N end S lake bald eagle
26‐Jun Loongoon violet green swallows
30‐Jun Montana Western Toad 3 toadlets! On platform.